Drilling tool



7 Sept. 24, 1940. P. A. WILLIAMS DRILLING TOOL Filed Jan. 25, 1939INVENTOR. I

HIS ATTORNEY.

Patented Sept. 24, 1940 Peter A. Williams, Northridge, Calif assignor toIngersoll-Rand Company, Jersey City, N. J, a corporation of New JerseyApplication January 23, 1939, Serial No, 252,364

2 Claims.

This invention relates to drilling tools, and more particularly to adrilling tool in which the cutting element is formed as areplaceablemember and suitably secured to the body portion of 5 the tool. 7

One object of the invention is to enable the cutting element to beexpeditiously secured to or removed from the drilling tool,

Another object is to eliminate the chances of 10 portion of the tool.

Other objects will be in part obvious and in part pointed outhereinafter.

In the drawing accompanying this specification and in which similarreference numerals refer to similar parts,

Figure 1 is a side elevation of the cutting end of the drilling toolconstructed in accordance with the practice of the invention,

Figure 2 is a similar view, partly broken away, showing the manner inwhich the cutting elements are secured in the body portion of thedrilling tool,

Figure 3 is an end view of the cutting portion of the drilling tool, and

Figure 4 is a view similar to Figure 2 showing a modified form of theinvention.

Referring more particularly to the drawing, designates, in general, adrilling tool shown, for the sake of simplicity of illustration, ashaving an integral upset body 2| of generally frustoconical shape toserve as the cutting end of the drilling tool.

The drilling tool has an axial channel 22 which 35 opens, in the presentinstance, into a groove 23 in the free end of the body 2| for conveyingcleansing fluid to the bottom of a drill hole for flushing the cuttingsfrom the working surface.

The groove 23 is of V-shape and its sides 24 converge toward andcooperate with inclined surfaces 25 to define a pair of V-shaped ribs 26that are in parallelism with respect to each other and extend across theend of the body portion 2|. In the longitudinal planes of the ribs 26and opening from the front ends thereof are slots 21 that extend fromone 'side of the tool to the other to receive cutting elements 28 whichseat against the bottoms of the slots 21 and are preferably fittedsnugly into the slots 21. The front ends of the cutting elements 28constitute the cutting portions thereof and are accordingly providedwith inclined surfaces 29 that. are preferably flush with the sides 24and the surfaces 25 and converge to define cutting edges 30. 55 Suitablemeans are provided for securing the the cutting element becoming loosein the body cutting elements 28 fixedly in the slots 21. To

this end the body 2| is provided with lateral apertures 3| which extendfrom opposite sides of the body-and each aperture 3| has a portion lyingon opposite sides of the slot 25 into which 5 they open. As a preferredarrangement the por tions of the apertures 3| lying between the slotsand the. axis of the drilling tool are concave merely, as for example ofthe shape and depth approximatelyequal to the length of the beveled 10point of the drill whereby the apertures 3| are formed. i

The apertures 3| are preferably so located as to open into the slots 21near the rearward ends of said slots, and in the cutting elements 28 are15 apertures 32 of larger diameter than the apertures 3| wherewith theywill be axially aligned in the assembled positions of the parts.

The apertures 3| and 32 serve as receptacles for securing members 33which initially are in a the form of cylindrical plugs of the formillustrated in the apertures on the left hand side of Figure 2. Thesecuring members 33 consist of malleable material and after beingdisposed in the apertures they are subjected to pressure, or .95percussive blows, on their outer ends 34 to cause portions of the plugsto be expanded into tight engagement with the walls of the apertures 3|and 32. In this way shoulders 35 are formed on the sides of the portionsof the plugs lying within 30 the apertures 32 to engage the sidesurfaces of the slots 21 for preventing endwise movement of the plugs 33and at the same time portions of the plugs are fitted tightly into theportions of the apertures 3| lying on opposite sides of 35 the slots toprevent movement of the cutting elements in the slots 21.

In order to provide a ready escape for the cuttings created bythe-cutting elements, longitudinally extending grooves 36 are formed inthe 40 body 2| at the ends of the groove 23 and additional clearance maybe provided between the body 2| and the hole being drilled by formingflat surfaces 31 on the portions of the body lying outside of the slots21.

In assembling the drilling tool the cutting elements are placed in thecorrect positions in the slots 21 so that they will seat firmly againstthe bottoms of the slots. The plugs 33 are then placed in position toseat in the bottoms of the apertures 3| and force is then applied toexpand the plugs firmly against the walls of the apertures 3| and 32.

In the event that it may be desired to remove the cutting elements fromthe body this may be .55

readily accomplished by hammer blows or other suitable force applied tothe sides of the cutting elements to shear oil the securing members. Theinner severed ends of the plugs will then ,drop out or may be readilydislodged from the shallow, tapered portions of the apertures 3| and theouter ends of the plugs may be removed by driving them into the slots21.

In the modified form of the invention illustrated in Figure 4, theaperture 3| lies entirely on one side of the slot 21, into which itopens. The aperture comprises an enlarged portion 33 adjacent the slot21 and'an outer reduced portion 39, and at the juncture of the portions33 and 39 is a shoulder 40 against which the expanded plug 33 seats toretain said plug in the apertures.

In this arrangement the inner end of the plug 33 is driven against theside of the slot 21 in securing the plug in the apertures, and inremoving the cutting elements 28 from the slot only a single line ofdivision is required through the plug 33.

I claim:

1. A drilling tool comprising a body having a slot and an apertureopening into the slot, a cutting tool in the slot having an aperture oflarger cross sectional dimensions than the body aperture, said aperturesbeing substantially in registry, and a malleable member insertable intoboth apertures and adapted to be permanently deformed at the largeraperture to prevent removal through the smaller aperture.

2. A drilling tool comprising a body having a l slot and an apertureopening into the slot, a cut-

